Legere, 54, has spent 32 years in the global telecommunications and technology industries. Most recently, he was the CEO of Global Crossing, a telecommunications company. During his time as CEO, he was able to achieve the company's first integrated global IP-based network. He also improved customer service and network operations at Global Crossing.

"I am thrilled to join T-Mobile and lead the company at such a pivotal time," said Legere. "T-Mobile is taking a number of significant steps to revitalize the business and I look forward to leading our team and partners to accelerate these efforts to become a force in our industry."

John Legere [Image Source: Bloomberg]

Before Legere, T-Mobile Chief Operating Officer Jim Alling took the helm as interim CEO. Alling stepped in for former T-Mobile CEO Phillip Humm, who left the company in June of this year. There were a few reasons for Humm's departure, including the fact that the AT&T/T-Mobile merger failed and led to continued financial losses for the company. In addition, Humm's family was stuck in Europe, which likely led to personal issues.

But starting September 22, Legere will step up to CEO and hopefully help T-Mobile out on the financial end. The Deutsche Telekom AG-owned company could also use some direction with its network, HSPA+. HSPA+ has had a difficult time struggling with faster, "true" 4G networks like Verizon and AT&T's LTE networks.

"John is a talented and proven executive who brings a successful track record of leading and operating consumer- and business-focused telecommunications and technology companies,” said René Obermann, CEO of Deutsche Telekom. “As T-Mobile moves forward with its strategic initiatives to improve its market position, including expanding its network coverage and initiating LTE service, John has obviously the right skillset to lead the business into the future. John’s experience in the telecommunication and technology industries at Global Crossing and Dell will enhance T-Mobile’s ability to deliver superior mobile experiences for our customers as the Company continues to strengthen its business. I am delighted to welcome John to T-Mobile and look forward to working with him to make T-Mobile a stronger competitor.”